Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

222-9+11+12:2*14+14 = ? ( )

Toán Lớp 8: b, ( x-y) mũ 2 + (3x+y) mũ 2 -2(y-2)(y+2)

Tháng Sáu 11, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: b, ( x-y) mũ 2 + (3x+y) mũ 2 -2(y-2)(y+2)

Comments ( 2 )

  1. hatuanlan
    hatuanlan
    11 Tháng Sáu, 2022 at 9:00 chiều
    Reply
    b, ( x-y)^2 + ( 3x +y)^2 – 2( y -2)( y+2)
    = x^2 – 2xy + y^2 + 9x^2 + 6xy + y^2 – 2(y^2 – 4)
    = x^2 – 2xy + y^2 + 9x^2 + 6xy + y^2 – 2y^2 + 8
    = ( x^2 + 9x^2 ) + ( -2xy + 6xy ) + ( y^2 + y^2 – 2y^2 ) + 8
    = 10x^2 + 4xy + 8

  2. myngocla
    myngocla
    11 Tháng Sáu, 2022 at 9:00 chiều
    Reply
    \text{(x-y)² +  (3x+y)² -2(y-2)(y+2) }
    \text{= x² – 2xy + y² +9x² + 6xy + y² – 2 ( y² – 4) }
    \text{= x² – 2xy + y² +9x² + 6xy + y² -2y² + 8 }
    \text{= 10x²  + 4xy + 8}

Leave a reply

222-9+11+12:2*14+14 = ? ( )

Ngọc Quý

About Ngọc Quý